Potency of nano-antibacterial formulation from Sargassum binderi against selected human pathogenic bacteria

Seaweeds constitutes an abundant marine reserve that can be harnessed as source of new pharmaceutical agents. Sargassum binderi Sonder ex J. Agardh is a brown seaweed that is predominantly available from December to March in the Red Sea, Jazan, Kingdom of Saudi Arabia (KSA). In this study, three extracts were isolated using three different techniques, and were subjected to antibacterial assay. The petroleum ether extract of Sargassum binderi was more effective against selected human pathogenic bacteria than the other extracts. Therefore, further studies were focused on developing oleic acid vesicles entrapped with the petroleum ether extract of Sargassum binderi, with the aim of enhancing its penetration property. Oleic acid vesicles were prepared by entrapping petroleum ether extract of Sargassum binderi using film hydration technique. The formulated vesicles were in nanoscale, and so were termed phyto-nanovesicles (PNVs). The spectrum of antibacterial activity of PNVs showed that it is a promising formulation against S. aureus, S. pyogenes, B. subtilis, E. coli, K. pneumoniae and P. aeruginosa. The microbial sensitivities to the PNVs was in the order E.coli > B. subtilis > S. aureus > S. pyogenes > K. pneumoniae > P. aeruginosa. Thus, the PNV formulation possesses promising and effective antimicrobial potential against human pathogenic bacteria

Somatic embryogenesis and plant regeneration in Wedelia calendulacea Less. an endangered medicinal plant

In this work, plant regeneration via somatic embryogenesis was achieved from leaf and internode derived callus of Wedelia calendulacea, an endangered medicinal plant. Primary callus was induced by culturing leaf disc and internode explant on Murashige and Skoog medium supplemented with 2.0 mg L-1 of 2,4-D under light condition. Transfer of embryogenic callus on a reduced concentration of 2,4-D facilitated somatic embryo development while calluses remained unorganized at the same 2,4-D level. A histological analysis confirmed somatic embryo by revealing the presence of a closed vascular system in the developing embryos and lack of a vascularconnection with surrounding callus tissues. Somatic embryos germinated into plantlets upon transfer on MS medium containing 1.0 mg L-1 BAP plus 0.5 mg L-1 GA3. Plantlets were acclimatized successfully and survived under soil condition. This is the first on somatic embryogenesis of W.calendulacea. This result could facilitate genetic transformation of this important medicinal plant.